Housing mount assembly for a roller cutter

ABSTRACT

A housing mount assembly for supporting a roller cutter is described. The housing mount assembly comprises a housing mount defining an outer surface for attaching to a housing and a profiled inner surface extending away from the outer surface, the profiled inner surface defining a channel extending in a longitudinal direction, and a seat support block extending away from the outer surface and defining a first seat support surface transverse to the channel, and a second seat support surface transverse to the first seat support surface. The housing mount assembly further comprises a removable seat mounted on the seat support surfaces and defining two transverse roller cutter shaft support surfaces whereby the removable seat and the seat support block together provide support for a roller cutter shaft.

This application is based upon International Application No.PCT/US2020/057159, filed Oct. 23, 2020, which claims priority benefitsto U.S. Provisional Patent Application No. 62/926,387 filed Oct. 25,2019 both entitled “HOUSING MOUNT ASSEMBLY FOR A ROLLER CUTTER,” whichis incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

A tunnel boring machine (“TBM”) is used to create tunnels in soil orrock. A conventional TBM includes a rotatably driven cutting head thatsupports a plurality of roller cutter assemblies, which are intended tobe replaced when worn down.

One type of roller cutter assembly is disclosed in FIG. 1 of US2018/0258764 to Lenaburg. However, this roller cutter assembly istypically welded onto the TBM, which makes in situ removal timeconsuming and difficult. Furthermore, the need to weld the roller cutterassembly to the TBM reduces the available options for materials that canbe used for the roller cutter assembly.

SUMMARY OF THE DISCLOSURE

According to a first aspect there is provided a housing mount assemblyfor supporting a roller cutter, the housing mount assembly comprising:(i) a housing mount defining an outer surface for attaching to a housingand a profiled inner surface extending away from the outer surface, theprofiled inner surface defining a channel extending in a longitudinaldirection, and a seat support block extending away from the outersurface and defining a first seat support surface transverse to thechannel, and a second seat support surface transverse to the first seatsupport surface; (ii) a removable seat mounted on the seat supportsurfaces and defining two transverse roller cutter shaft supportsurfaces whereby the removable seat and the seat support block togetherprovide support for a roller cutter shaft; and (iii) an engagementdevice for releasably holding the removable seat in proximity to theseat support surfaces.

The engagement device may be located between the removable seat and theouter surface.

The housing mount may further define a recess in which the engagementdevice is mounted. The recess may be located above the seat supportblock so that it is located behind the removable seat when assembled.

The engagement device may comprise a magnet, a spring clip coupling, asnap fit coupling, a deformable (elastic) material mounted in aperimeter of the recess to provide an interference fit for the removableseat when inserted therein, an adhesive for coupling the removable seatto the recess or other portion of the housing mount, a bolt extendingthrough an aperture defined by the removable seat and engaging with acomplementary thread in the profiled inner surface of the housing mount,or any other convenient mechanical coupling.

Where the engagement device comprises a bolt extending through anaperture, the aperture may comprise a slot, for example, extendinggenerally parallel with the channel, to allow some movement of theremovable seat during use.

The bolt may initially be located at a lower portion of the slottedaperture to allow the bolt to rise up the slotted aperture as theremovable seat wears during use.

In some embodiments, one purpose of the engagement device may hold theremovable seat in position during assembly of the parts of a rollercutter assembly, where the roller cutter assembly comprises a rollercutter mounted between opposing complementary housing mounts, and heldtogether by two retaining couplings, optionally in the form of bolt andwedge sets, each bolt being partially located within, or adjacent to, achannel.

The second seat support surface may be obliquely transverse to the firstseat support surface. In particular, the second seat support surface anda removable seat sidewall may define complementary surfaces to enablethe second seat support surface to assist in retaining the removableseat in place. For example, the second seat support surface may betapered inwardly (i.e. inclined towards the channel as the seat supportsurface extends away from the outer surface); and the removable seat maydefine a tapered sidewall corresponding to the tapered second seatsupport surface so that the removable seat is retained in place by themutual interaction of the tapered surfaces.

The housing mount may comprise cast or forged iron or steel tofacilitate welding of the housing mount to a housing of a tunnel boringmachine.

The housing mount assembly may further comprise a removable insertmounted on an opposite side of the channel to the removable seat,wherein part of the retaining coupling acts against the removable insertand an opposite part of the retaining coupling acts against a shaft ofthe roller cutter.

The removable seat (and or the removable insert) may comprise a highhardness metal or alloy as there is no requirement to weld the removableseat. This has the advantage of improving the wear resistance, andtherefore the useful life, of the housing mount assembly.

According to a second aspect there is provided an assembly for a rollercutter, the assembly comprising: a pair of complementary housing mountsas set forth in the first aspect.

According to a third aspect there is provided a roller cutter assemblycomprising a roller cutter mounted in the assembly of the second aspectand held in place by a pair of retaining couplings.

Each retaining coupling may comprise: (i) a bolt extending through thelongitudinal channel securing (ii) a wedge at one end thereof and (iii)a clamp block abutting a clamping surface defined by the housing mount.The wedge may abut an angled face of the roller cutter shaft to maintainthe roller cutter shaft in contact with the transverse roller cuttershaft support surfaces defined by the removable seat.

According to a fourth aspect there is provided a tunnel boring machinecomprising a plurality of roller cutter assemblies as set forth in thethird aspect.

It should now be appreciated that when a roller cutter assembly has worndown due to the removable seat wearing beyond a usable point, theremovable seat can be easily removed and the roller cutter assemblyre-assembled without requiring welding joints to be removed; therebygreatly speeding up the process of replacing a worn down seat.

It should now also be appreciated that the removable seat can be madefrom a very hard material because it does not need to be welded; therebyallowing the useful life of the seat to be increased.

DESCRIPTION OF THE DRAWINGS

These and other aspects will now be described, by way of example only,with reference to the accompanying drawings, in which:

FIG. 1 is a simplified, exploded perspective view of part of a rollercutter assembly according to one embodiment of the present invention;

FIG. 2 is a simplified, front elevation view of the roller cutterassembly parts of FIG. 1 in assembled form (with one part shown partlyin broken line);

FIG. 3 is a simplified, side view of the roller cutter assembly parts ofFIG. 1 in assembled form;

FIG. 4 is a simplified, plan view of a complete roller cutter assemblycomprising the housing mount assembly parts and roller cutter shown inFIG. 1 in assembled form and a complementary housing mount; and

FIG. 5 is a simplified perspective view of an alternative part for usein a roller cutter assembly according to another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIGS. 1 to 3 , which show various views of parts ofa roller cutter assembly 10 according to one embodiment of the presentinvention. The roller cutter assembly 10 comprises a pair ofcomplementary housing mounts 12 (only one of which (12 a) is shown inFIGS. 1 to 3 , the other housing mount is shown in FIG. 4 ), each ofwhich is a mirror image of the other. For simplicity and clarity ofexplanation, only one of the housing mounts 12 a will be describedbecause the other housing mount 12 b is identical (other than being themirror image of the one being described). The housing mounts 12 aretypically permanently fixed to the TBM cutter wheel (not shown), usuallyby a welding joint but a mechanical coupling may be used. The housingmounts 12 are typically made of steel, but other materials may be used.

Reference is also made to FIG. 4 , which is a simplified, plan view of acomplete roller cutter assembly comprising the parts of FIG. 1 and thecomplementary housing mount 12 b, all in assembled form.

The housing mount 12 a comprises an outer surface 14 (best seen in FIGS.3 and 4 ), and a profiled inner surface 16 on an opposite side of thehousing mount 12 to the outer surface 14. The purpose of the profiledinner surface 16 is to secure in place various removable parts of theroller cutter assembly 10. These removable parts include: a rollercutter 20, a seat 22, an insert 24, and a retaining coupling 26.

The combination of the housing mount 12 a, the seat 22, and the insert24 are referred to as a housing mount assembly. The combination of twocomplementary housing mount assemblies having the roller cuttertherebetween retained in place by the retaining coupling 26 is a rollercutter assembly 10.

Returning to the housing mount 12 a, the profiled inner surface 16thereof partially defines a channel 30 extending in a longitudinaldirection (indicated by broken line 32). In particular, the channel 30is defined by a seat support block 34 and an insert support block 36 ofthe profiled inner surface 16, and also by the seat 22 and the insert 24when installed. FIG. 1 illustrates by broken leader lines where the seat22 and the insert 24 are located on the housing mount 12 a when fullyassembled.

The seat 22 and optionally the insert 24 are made from a high hardnessalloy and are held, at least temporarily during the assembly process, inplace by an engagement device (or mechanism) 40. In this embodiment, theengagement device 40 comprises magnetised portions (shown delineated bybroken line 40) of the housing mount 12 that attract the seat 22 and theinsert 24. High hardness alloys can be used because there is norequirement to weld the seat 22 or insert 24 to the housing mount 12. Inother embodiments, the housing mount 12 may define a recess behind thefinal location of the seat 22, and a magnet may be located in thisrecess, or an alternative engagement device, such as a spring clip maybe located in this recess.

In other embodiments, the seat 22 and/or insert 24 may include amagnetised portion (optionally in the form of a removable magnet or alocal magnetised area) that engages with the housing mount 12 (whichincludes portions attracted to magnets and located opposite the seat andinsert magnetised portions), thereby providing an engagement device.

When the seat 22 and insert 24 are temporarily retained in place, theroller cutter 20 (which is a conventional roller cutter) may be mountedon the seat 22 (best seen in FIG. 2 ). For clarity (to prevent obscuringother parts), the roller cutter 20 is shown in broken line.

The roller cutter 20 is positioned to engage the tunnel face duringtunnel boring operations. The roller cutter 20 comprises a cutter ring50 mounted on a hub 52 rotatable about a shaft 54. The shaft 54 definesa pair of mutually transverse flat surfaces 56 a,b and an angled surface58 opposite an area where the flat surfaces 56 a,b are closest.

The seat support block 34 defines a pair of engagement surfaces 60 a,b(best seen in FIGS. 1 and 4 ) for receiving the seat 22. The firstengagement surface 60 a (also referred to as the horizontal seat supportsurface) is transverse (generally horizontal in this embodiment) to thelongitudinal direction 32; the second engagement surface 60 b (alsoreferred to as the vertical seat support surface) is generally parallelto the longitudinal direction 32, but it is angled inwards (best seen inFIG. 4 ). In other words, the portion of the vertical engagement surface60 b that is nearest the outer surface 14 is further from the channel 30than the portion of the vertical engagement surface 60 b that isfurthest from the outer surface 14.

The seat 22 also defines a pair of outer support surfaces 62 a,b (alsoreferred to as base 62 a and sidewall 62 b), and a pair of inner supportsurfaces 64 a,b (also referred to as shaft support surfaces).

The base 62 a is complementary, and of similar dimensions, to thehorizontal seat support surface 60 a, and the sidewall 62 b is angled ina complementary manner (and is of similar dimensions) to the verticalseat support surface 60 b, thereby providing a closely fittingengagement when the seat 22 is mounted on the seat support block 34. Thecomplementary angles of the sidewall 62 b and the vertical seat supportsurface 60 b function as a draft to ensure that the seat 22 is hinderedfrom moving away from the housing mount 12.

The shaft support surfaces 64 a,b of the removable seat 22 are mutuallytransverse (horizontal and vertical in this embodiment) and of similardimensions to the shaft flat surfaces 56 a,b, but are slightly longer(best seen in FIG. 2 ), thereby ensuring a close-fitting connection.

In a similar way to the seat support block 34, the insert support block36 defines a pair of insert support surfaces 66 a,b for receiving theinsert 24. The horizontal surface 66 a is flat, and the vertical surface66 b is angled in an opposite (complementary) manner to the verticalseat support surface 60 b (best seen in FIG. 4 ).

The insert 24 defines a pair of outer support surfaces 68 a,b (alsoreferred to as base 68 a and sidewall 68 b), and an inner supportsurface 70.

The insert base 68 a is complementary, and of similar dimensions, to thehorizontal insert support surface 66 a, and the insert sidewall 68 b isangled in a complementary manner (and is of similar dimensions) to thevertical insert support surface 66 b, thereby providing a closelyfitting engagement when the insert 24 is mounted on the insert supportblock 36. The complementary angles of the insert sidewall 68 b and thevertical insert support surface 66 b function as a draft to ensure thatthe insert 24 is hindered from moving away from the housing mount 12.

The seat support block 34 also defines a clamping surface 72 atransverse to the longitudinal direction 32 and at an opposite end ofthe seat support block 34 to the horizontal seat support surface 60 a.

The insert support block 36 also defines a clamping surface 72 btransverse to the longitudinal direction 32 and at an opposite end ofthe insert support block 36 to the horizontal insert support surface 66a.

To assemble the parts, the seat 22 is located on the seat support block34, the insert 24 is located on the insert support block 36 (both areheld in place by the magnetised portions 40), and then the retainingcoupling 26 is used to move the roller cutter 20, seat 22 and insert 24into the correct positions and to hold them in place on a permanentbasis.

The retaining coupling 26 comprises a wedge 80 and a clamp block 82releasably coupled together by a threaded bolt 84 that passes throughapertures in the wedge 80 and clamp block 82, and is secured by a pairof nuts 86.

The wedge 80 defines an upright surface 90 parallel to the longitudinaldirection 32 and an angled surface 92. The wedge angled surface 92defines the same angle as the shaft angled surface 58, and the wedgeupright surface 90 matches the insert inner support surface 70, toensure a close-fitting connection.

When the shaft 54 is located on the seat 22 (which is mounted on theseat support block 34) and the insert 24 is located on the insertsupport block 36, then the wedge 80 can be placed between the shaft 54and the insert 24, the bolt 84 can be inserted through both the wedge 80and the clamp block 82 (which abuts the clamping surfaces 72 a,b), andthen the pair of nuts 86 can be tightened.

Tightening the nuts 86 urges the wedge 80 downwards, which urges theshaft 54 against the removable seat 22. The first draft provided by thesidewall 62 b and the vertical seat support surface 60 b, and the seconddraft provided by insert sidewall 68 b and the vertical insert supportsurface 66 b, assist in maintaining the roller cutter 20, seat 22,insert 24, and retaining coupling 26 in position.

A complementary housing mount 12 can then be coupled to the other sideof the shaft 54 in a similar manner to provide a complete roller cutterassembly ready for installation in a TBM.

A roller cutter assembly is subjected to very high forces during tunnelboring operations. One typical failure mechanism is the point at whichthe shaft of a roller cutter is supported on a housing mount. Thisembodiment has the advantage that the roller cutter assembly 10 can beeasily disassembled and the worn seat 22 easily removed and replacedwith a new seat 22.

Reference is now made to FIG. 5 , which is a perspective view of analternative removable seat 122. The removable seat 122 couples to ahousing mount 112 a (similar to housing mount 12 a) defining a screwthreaded aperture therein (shown as broken line 123, which is in asimilar location to the engagement device 40 location in FIG. 1 ). Theremovable seat 122 defines an aperture 125 in the form of a slotextending generally parallel to the channel 30 (i.e. in the longitudinaldirection indicated by broken line 32 in FIG. 1 ). A bolt 127, having acomplementary thread to screw threaded aperture 123, extends through theslot 125 (along axis 129) to secure the removable seat 122 in placeagainst the housing mount 112 a. The bolt 127 and screw threadedaperture 123 provide an engagement device to retain the removable seat122 in position.

A base 162 a of the removable seat 122 rests on a first engagementsurface 160 a (also referred to as the horizontal seat support surface160 a). The slot 125 is configured such that the bolt 127 is initiallynear the lower end of the slot 125. As the removable seat 122 wearsduring use, the wear primarily occurs at the base 162 a, which resultsin the removable seat 122 moving downwards, and the bolt 127 effectivelyrising upwards in the slot 125. The slot 125 therefore allows theremovable seat 122 to have a degree of movement during operation of theroller cutter assembly.

In the foregoing description of certain embodiments, specificterminology has been used for the sake of clarity. However, thedisclosure is not intended to be limited to the specific terms soselected, and it is to be understood that each specific term includesother technical equivalents which operate in a similar manner toaccomplish a similar technical purpose. Terms such as “upper” and“lower”, “above” and “below”, “vertical” and “horizontal” and the likeare used as words of convenience to provide reference points withrespect to the Figures, and are not to be construed as limiting terms,nor to imply a required orientation of the assembly.

In this specification, the word “comprising” is to be understood in its“open” sense, that is, in the sense of “including”, and thus not limitedto its “closed” sense, that is the sense of “consisting only of”. Acorresponding meaning is to be attributed to the corresponding words“comprise”, “comprised” and “comprises” where they appear.

The preceding description is provided in relation to several embodimentswhich may share common characteristics and features. It is to beunderstood that one or more features of any one embodiment may becombined with one or more features of the other embodiments. Inaddition, any single feature or combination of features in any of theembodiments may constitute additional embodiments.

In addition, the foregoing describes only some embodiments of theinventions, and alterations, modifications, additions and/or changes canbe made thereto without departing from the scope of the disclosedembodiments, the embodiments being illustrative and not restrictive.

List of Numerals Roller cutter assembly 10 Vertical seat support surface60b Housing mount 12, 112 Seat base 62a, 162a Outer surface 14 Seatsidewall 62b Profiled inner surface 16 Seat shaft support surfaces 64a,b Roller cutter 20 Horizontal insert support surface 66a Seat 22, 122Vertical insert support surface 66b Insert 24 Insert base 68a Retainingcoupling 26 Insert sidewall 68b Channel 30 Inner support surface 70Longitudinal direction 32 Clamping surface 72a, b Seat support block 34Wedge 80 Insert support block 36 Clamp block 82 Engagement device 40Threaded bolt 84 Cutter ring 50 Pair of nuts 86. Hub 52 Wedge uprightsurface 90 Shaft 54 Wedge angled surface 92 Shaft flat surfaces 56a, bInsert upright surface 94 Angled surface 58 Screw threaded aperture 123Horizontal seat support Aperture (slot) 125 surface 60a, 160a Bolt 127Bolt axis 129

1. A housing mount assembly for supporting a roller cutter, the housingmount assembly comprising: (i) a housing mount defining an outer surfacefor attaching to a housing and a profiled inner surface extending awayfrom the outer surface, the profiled inner surface defining a channelextending in a longitudinal direction, and a seat support blockextending away from the outer surface and defining a first seat supportsurface transverse to the channel, and a second seat support surfacetransverse to the first seat support surface; (ii) a removable seatmounted on the seat support surfaces and defining two transverse rollercutter shaft support surfaces having an internal corner therebetweenwhereby the removable seat transverse roller cutter shaft supportsurfaces provide support for a pair of mutually transverse flat surfacesof a roller cutter shaft; and (iii) an engagement device for releasablyholding the removable seat in proximity to the seat support surfaces. 2.A housing mount assembly according to claim 1, wherein the engagementdevice is located between the removable seat and the outer surface, andthe housing mount further defines a recess in which the engagementdevice is mounted.
 3. A housing mount assembly according to claim 2,wherein the recess is located above the seat support block so that theengagement device is located behind the removable seat when assembled.4. A housing mount assembly according to claim 3, wherein the engagementdevice comprises: a magnet or a magnetised portion of the housing mountor the removable seat, a spring clip coupling, a snap fit coupling, adeformable material mounted in a perimeter of the recess to provide aninterference fit for the removable seat when inserted therein, a boltextending through an aperture defined by the removable seat and engagingwith a complementary thread in the profiled inner surface of the housingmount, or an adhesive for coupling the removable seat to the recess orother portion of the housing mount.
 5. A housing mount assemblyaccording to claim 4, wherein the bolt extends through a slot-shapedaperture defined by the removable seat, with the slot extending in thelongitudinal direction, and engaging with the complementary threaddefined by the profiled inner surface, thereby allowing the bolt to movewithin the slot-shaped aperture during use of the housing mountassembly.
 6. A housing mount assembly according to claim 1, wherein thesecond seat support surface is obliquely transverse to the first seatsupport surface, and the second seat support surface and a removableseat sidewall define complementary surfaces to enable the second seatsupport surface to assist in retaining the removable seat in place.
 7. Ahousing mount assembly according to claim 1, wherein the housing mountassembly further comprises a removable insert mounted on an oppositeside of the channel to the removable seat.
 8. A housing mount assemblyaccording to claim 7, wherein the removable insert comprises a highhardness metal.
 9. A housing mount assembly according to claim 1,wherein the removable seat comprises a high hardness metal.
 10. Ahousing mount assembly according to claim 1, wherein the removable seatcomprises less than 50% of the height of the part of the seat supportblock on which the removable seat is supported.
 11. A roller cutterassembly, the assembly comprising: (i) a first housing mount defining anouter surface for attaching to a housing and a profiled inner surfaceextending away from the outer surface, the profiled inner surfacedefining a channel extending in a longitudinal direction, and a seatsupport block extending away from the outer surface and defining a firstseat support surface transverse to the channel, and a second seatsupport surface transverse to the first seat support surface; (ii)second housing mount comprising a mirror image of the first housingmount; (iii) a pair of removable seats, each removable seat (a) beingmounted on the seat support surfaces of the housing mounts, and (b)defining two transverse roller cutter shaft support surfaces whereby theremovable seat and the seat support block together provide support for aroller cutter shaft; (iv) a pair of engagement devices for releasablyholding the removable seat in proximity to the seat support surfaces;(v) a roller cutter mounted on the pair of removable seats and includinga shaft defining a pair of mutually transverse flat surfaces at each endthereof, and an angled surface opposite an area where the flat surfacesare closest; and (vi) a pair of longitudinal couplings; wherein each ofthe pair of removable seats has a first roller cutter shaft supportsurface transverse to a second roller cutter shaft support surface suchthat the first and second roller cutter shaft support surfaces providean internal corner for the pair of mutually transverse flat surfaces ofthe roller cutter shaft.
 12. A roller cutter assembly according to claim11, wherein each longitudinal coupling comprises: a bolt extendingthrough the longitudinal channel and securing a wedge at one end thereofand a clamp block abutting a clamping surface defined by the housingmount.
 13. A roller cutter assembly according to claim 12, wherein thewedge abuts an angled face of a roller cutter shaft to maintain theroller cutter shaft in contact with the removable seat.
 14. A rollercutter assembly according to claim 13, wherein the roller cutterassembly comprises a pair of removable inserts.
 15. A roller cutterassembly according to claim 14, wherein the wedge abuts the removableinsert and an opposite part of the wedge acts against the roller cuttershaft.
 16. A roller cutter assembly according to claim 15, wherein eachpair of inserts defines an inner support surface mounted opposite thecorresponding removable seat.
 17. A tunnel boring machine comprising aplurality of roller cutter assemblies according to claim 11.